bug#15880: Compute C declarations for DEFSYMs automatically.

[Eli Zaretskii]

> From: Andreas Schwab <schwab@linux-m68k.org>
> Cc: Paul Eggert <eggert@cs.ucla.edu>,  15880@debbugs.gnu.org
> Date: Fri, 09 Jan 2015 21:08:56 +0100
> 
> Eli Zaretskii <eliz@gnu.org> writes:
> 
> >> Date: Fri, 09 Jan 2015 08:33:53 -0800
> >> From: Paul Eggert <eggert@cs.ucla.edu>
> >> CC: rgm@gnu.org, 15880@debbugs.gnu.org
> >> 
> >> Eli Zaretskii wrote:
> >> > Could we instead just keep the previous semantics of XIL and XLI,
> >> > please?  They are used in a few places outside lisp.h, so now all of
> >> > those places need to be audited and most probably changed.  Why isn't
> >> > it better to change the implementation of just 2 macros instead?
> >> 
> >> XIL and XLI haven't changed, and have the same semantics as before: they 
> >> convert 
> >> between Lisp_Object and EMACS_INT without altering the bits (i.e., they 
> >> are 
> >> no-ops at the machine level).
> >
> > That's not what their previous semantics was.  They converted between
> > a Lisp integer and EMACS_INT.
> 
> No, that's called XINT.

OK, a C integer, not EMACS_INT.  But you already knew that, of course.